Fallon, 38, and Juvonen, 46, married in 2007 after meeting through mutual friend Drew Barrymore, who co-produced "Charlie's Angels" and "50 First Dates" with Juvonen through their company Flower Films.

Fallon thanked his fans for the well-wishes and said he's already addicted to showing people pictures of his baby.

"Thank you so much, I hope I don't screw this up," he said. "I'm just so happy."

The comedian also quipped about the "other baby" making headlines this week.

"We haven't had time to respond to everyone's calls and messages but, yes, William and Kate, we'll definitely set up a playdate — stop bothering me!" Fallon said. "I saw the invitation on the easel, yes!"